When I was a child and teenager, I normally spoke with a northern Yorkshire/Durham borders accent at home, as did my siblings, but whenever we went out of the house we spoke with our White /African accent. Eventually we all but lost our English accent.
My parents accent never changed but when we came back here we were looked upon as snobs because we spoke with such a clipped accent.
Oh, and in both South Africa and Rhodesia/Zimbabwe there was loads of chanting and foot stomping dances.